I use the battery pack on a Nikon D90, the label says: EN-EL-3 / Li-ion 7.4 V / 1500 mAh (milli Ampere hour in 1500). The charge acquired last long, I found that this battery has almost no self-discharge, I happened to leave the camera steady for several weeks, the charge is intact. A Use with charger referenced to MH + 18a. it takes forty minutes of charging with a battery that remains at 25% capacity.